The present invention relates to a catheter apparatus and more particularly, to an access catheter apparatus that enables minimally invasive surgery to be performed in the uterus or selective examination of the fallopian tubes.
Access catheters can be used in non-surgical diagnostic procedures that enable the examination of the uterus and fallopian tubes. One such procedure known as hysterosonography, employs contrast agents and ultrasound imaging techniques for viewing the anatomical structures of the uterus. In hysterosonography, a fine flexible catheter equipped with an inflatable balloon is used to gain access into the uterus. This is accomplished by inserting the catheter into the cervical canal or the uterus and inflating the balloon with saline to block the cervical canal. A contrast agent, such as saline, is then injected through the catheter to fill the uterus so that it can be viewed using ultrasound imaging techniques.
It may also be desirable to use an access catheter to gain access into the uterus for the purpose of carrying out a minimally invasive surgical procedure, such as a biopsy. In such a procedure, the access catheter is inserted through the cervix into the uterus. A contrast agent, such as saline or water, is injected through the catheter to fill the uterus so that any suspected pathology can be viewed using ultrasound imaging techniques. A surgical instrument, such as a biopsy needle or snare, is then passed through the catheter and into the uterus and manipulated to perform the surgery.
Another desirable use for an access catheter is as a conduit for a smaller diameter catheter used for selective examination of fallopian tubes. Such a catheter is passed through the access catheter and manipulated into the entrance of either fallopian tube. Contrast medium is then injected through the inner catheter to determine the degree of patency of the tube. In this application, X-ray techniques can be used as well as ultrasound procedures.
Access catheters that are suitable for performing minimally invasive surgery in the uterus or selective examination of the fallopian tubes must be stable when positioned in the cervical canal. Previous guided access catheter designs typically employ two inflatable, distally located balloons for stabilizing the catheter. Such catheters are constructed with multiple lumens, two for inflating the balloons, one for inserting the surgical instrument, and one for injecting the contrast agent. These multi-lumen catheter designs necessarily have relatively large outer diameters, which typically measure about 4 mm (12 french). The relatively large outer diameters of these prior catheter designs can cause patient discomfort and or trauma. Moreover, these designs are relatively complex, thus increasing the cost of the device.
Accordingly, an access catheter apparatus for performing minimally invasive surgery in the uterus or selective examination of the fallopian tubes is needed that overcomes the problems associated with previous access catheter designs.
The invention is directed to a catheter apparatus for gaining access into the uterine cavity in order to perform minimally invasive surgery in a uterus or selective examination of the fallopian tubes. The catheter apparatus comprises a single-lumen tubular body, and an elongated balloon disposed distally on the tubular body for insertion into a cervical canal of the uterus. The balloon is affixed to the tubular body and sealed with a fixed residual volume of fluid. The balloon includes opposing portions that occlude openings of the cervical canal when fluid displacement in one portion of the balloon causes other portions of the balloon to inflate.
One aspect of the catheter apparatus involves a fluid displacement sleeve, which is slidably disposed over the single-lumen tubular body. The sleeve is moveable over the elongated balloon to displace fluid in the proximal portion of the balloon thereby inflating the portions of the balloon which are adjacent the opposite openings of the cervical canal when the balloon is inserted therein.
In another aspect of the catheter apparatus, the inflated portions of the balloon define a barbell-shape balloon structure when the balloon is inflated in the cervical canal.
In a further aspect of the catheter apparatus, a surgical instrument insertion adapter assembly is disposed at a proximal end of the single-lumen tubular body.
In still a further aspect of the catheter apparatus, a removable stylet is optionally provided for stiffening the single-lumen tubular body to facilitate insertion thereof in the cervical canal.